Joint manufacturing costs: $900,000

quantity produced        price at split-off
grade                            (board feet)          (per 1,000 board ft.)
firsts and seconds      1,500,000                                          $300
no. 1 common                3,000,000                                              225
no. 2 common                1,875,000                                              140
no. 3 common                1,125,000                                              100
total                                            7,500,000

allocate the joint manufacturing costs to each grade, and calculate the cost per board foot for each grade:

(a) using the physical units method of allocation.
(b) using the sales-value-at-split-off method. which method should the mill use? explain. what is the effect on the cost of each proposed job if the mill switches to the sales-value-at-split-off method? .